(36)*(20)=(x+6)*(2x-6)

Solution for (36)*(20)=(x+6)*(2x-6) equation:

(36)(20)=(x+6)(2x-6)

We move all terms to the left:

(36)(20)-((x+6)(2x-6))=0

We multiply parentheses ..

-((+2x^2-6x+12x-36))+3620=0


We calculate terms in parentheses: -((+2x^2-6x+12x-36)), so:

(+2x^2-6x+12x-36)

We get rid of parentheses

2x^2-6x+12x-36

We add all the numbers together, and all the variables

2x^2+6x-36

Back to the equation:

-(2x^2+6x-36)


We get rid of parentheses

-2x^2-6x+36+3620=0

We add all the numbers together, and all the variables

-2x^2-6x+3656=0

a = -2; b = -6; c = +3656;
Δ = b2-4ac
Δ = -62-4·(-2)·3656
Δ = 29284
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{29284}=\sqrt{4*7321}=\sqrt{4}*\sqrt{7321}=2\sqrt{7321}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-6)-2\sqrt{7321}}{2*-2}=\frac{6-2\sqrt{7321}}{-4}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-6)+2\sqrt{7321}}{2*-2}=\frac{6+2\sqrt{7321}}{-4}
$